Pylaisia contains 15 species primarily of the north temperate region; three species in the Neotropics. The genus is distinguished by the curved short branches, crowded, imbricate, homomallous or falcate-secund leaves with quadrate to subquadrate alar cells in a well defined group, erect cylindrical capsules with the endostome often adhering partially or fully to the exostome. Pylaisia has recently been conserved over the name Pylaisiella.